Gaming chips and table game security system

ABSTRACT

Gaming chips are provided with embedded radio frequency identification (“RFID”) tags incorporated into a gaming chip for identifying and tracking the gaming chips within a casino, and even upon a gaming table. The gaming chips have a body in the shape of a disc which has a loss tangent of 0.0078 or less, and more preferably of 0.007 or less. For chips operating at 900 MHz, the body has a dielectric constant of 5 or less, and preferably 3-5. For chips operating at 2.45 GHz, the body has a dielectric constant of 5-8. Preferably, the body is made of a blend of plastic, such as PVC, and a dielectric ceramic. The RFID is preferably sandwiched between layers of a high frequency circuit material including top and bottom layers and a center layer have a hole for receiving the RFID. Preferably, the layers of high frequency circuit material have a dielectric constant of 2.5-4 and a loss tangent of 0.002-0.006.

RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 12/221,493 filed Aug. 4, 2008, now U.S. Pat. No.9,589,220 issued on Mar. 7, 2017, which in turn is a,continuation-in-part application of U.S. Provisional Application No.60/963,345 filed on Aug. 4, 2007.

BACKGROUND OF THE INVENTION

The present invention relates to casino gaming. More specifically, thepresent invention relates to systems and methods for conducting andtracking transactions at table games and other locations on the floor ofa casino or other gaming establishment. Casino gaming is a multi billiondollar industry in which table games remain an immensely popular form ofgaming and a substantial source of revenue. Table games include Poker,Blackjack, Craps, Roulette, Pai-Gow, Caribbean Stud, Spanish 21 and Letit Ride, among many others.

A primary concern of casinos is the management and tracking of gamingchips, markers or plaques used by players and casino personnel to makewagers, pay out winnings and the like. In the United States, gamingchips typically come in various denominations such as one dollar, fivedollars, twenty-five dollars, one hundred dollars, one thousand dollarsand ten thousand dollars. Other countries use a wide variety ofdenominations and currencies for gaming chips. Due to the gaming chip'svalue and importance in tracking their use, various systems have beendeveloped for tracking gaming chip transactions. For example, numerousU.S. patents describe the use of radio frequency identification (“RFID”)tags incorporated into a gaming chip for identifying and tracking thegaming chips within a casino, and even upon a gaming table. Gaming chipsincluding an RFID tag are read using RFID readers employing variousantenna in a casino, such as within a casino vault, casino chip tray orcasino gaming table. To track player involvement, it is known to providea separate antenna reader at each player position.

Unfortunately, basic RFID gaming chips suffer from several drawbacks.For example, the various RFID antenna within a gaming table often failto detect gaming chips nearby, but will often read gaming chips at otherpositions. Alternatively, gaming chips can be read by more than oneantenna providing a false indication that a gaming chip is in two placesat once. In addition, it has been proven to be extremely difficult toread all of the chips within a large stack of chips. A large number ofrandomly unstacked chips is also difficult to read by RFID antenna.

Thus, there is a need for a system for accurately and automaticallytracking gaming chips through a casino and particularly at a gamingtable. Furthermore, it would be desirable to provide improved gamingchips which incorporate greater security features within the RFID tags.

SUMMARY OF THE INVENTION

Previously, gaming chips, including those that have incorporated anRFID, have typically been made of polyvinylchloride (PVC).Unfortunately, PVC is not particularly conducive to the operation of animbedded RFID. More particularly, it has been discovered that thedielectric constant is not particularly conducive to the operation ofthe RFID. In particular, PVC has a dielectric constant of 1-3 and a losstangent of greater than 0.0008. When blended with a common filler,barium sulfate, the traditional gaming chip typically has a dielectricconstant of greater than 4 and a loss tangent of greater than 0.008. Ithas been discovered that this loss tangent is too high for optimaloperation of an embedded RFID.

The present invention is directed to a gaming chip constructed foroptimal operation of an internally embedded RFID. The gaming chipincludes a body forming the exterior of the gaming chip. In addition,the gaming chip includes an internal RFID which is encapsulated by thegaming chip's body during the manufacturing process.

The gaming chip's body is made of a material having a loss tangent of0.0078 or less, and more preferably a loss tangent of 0.007 or less. Aloss tangent of 0.005 would be even more optimal. The body has a losstangent within this range regardless of the operational frequency of theembedded RFID. However, the dielectric constant for the gaming chip'sbody may differ depending on the frequency band within which the RFID isoperating.

Preferably, the RFID operates at the 900 MHz, 2.45 GHz or 5.8 GHzoperational bands specified by the Federal Communications Commission(“FCC”). For gaming chips incorporating an RFID operating at 5.8 GHz, itis desirable that the gaming chip's body be manufactured of a materialhaving a loss tangent of 0.002 or less, and more preferably of amaterial having an extremely low loss tangent of less than 0.001.

Where the gaming chip incorporates an RFID operating at a frequency bandof 900 MHz, it is preferred that the body have a dielectric constant of5 or less. More preferably, it is preferred that the body's dielectricconstant be between 3-5. In the event that the gaming chip includes anRFID intended to operate at the 2.45 GHz range, it is preferred that thebody has a dielectric constant of 5-8.

The gaming chip's body may be made from a variety of materials. However,it is preferred that the body be made of a blend of plastic and adielectric ceramic. A preferred plastic is polyvinylchloride (PVC).Meanwhile, preferred dielectric ceramics include aluminum oxide(alumina), magnesium titinate, zinc oxide, zirconium barium titanate,strontium titanate (ST), calcium titanate (CT), magnesium titanate (MT),calcium magnesium titanate (CMT), zinc titanate (ZT), lanthanum titanate(TLT), and neodymium titanate (TNT), barium zirconate (BZ), calciumzirconate (CZ), lead magnesium niobate (PMN), lead zinc niobate (PZN),lithium niobate (LN), barium stannate (BS), calcium stannate (CS),magnesium aluminium silicate, magnesium silicate, barium tantalate,titanium dioxide, niobium oxide, zirconia, silica, sapphire, berylliumoxide, and zirconium tin titanate, and combinations thereof.

The RFID may be embedded within the gaming chip's body employing varioustechniques known to those skilled in the art. However, existing premiergaming chips are manufactured by compression molding a blend of PVC andbarium sulfate under extreme pressure and temperature. Typical RFIDscannot withstand the pressure which would be encountered within atraditional compression molding process. Accordingly, it is preferredthat the RFIDs be placed within a protective capsule prior towithstanding a compression molding process within the formation of thegaming chip's body. The protective capsule may take various forms.However, it is preferred that the protective capsule be made of amaterial having a dielectric constant of between 2-5 and a loss tangentof 0.001-0.0078. Even more preferably, the capsule for protecting theRFID has a dielectric constant of 2.5-4 and a loss tangent of0.02-0.006. In a preferred embodiment, the protective capsule is made byproviding three layers of high frequency circuit material. Preferably afirst layer of high frequency circuit material is positioned above theRFID. A second layer of high frequency circuit material is positionedbelow the RFID. Finally, a third layer of high frequency circuitmaterial is formed with a center hole for receiving the RFID. The threelayers are affixed together with the RFID positioned within the centerlayer's central hole to completely encapsulate the RFID for protectionwithin a compression molding process.

Advantageously, the gaming chip is optimally constructed for operationof an embedded RFID.

It is thus an object of the present invention to provide a gaming chipwhich can be tracked within a casino environment.

It is still an additional object of the present invention to provide agaming chip which is inexpensive and easily manufactured.

Other features and advantages of the present invention will beappreciated by those skilled in the art upon reading the detaileddescription which follows.

DETAILED DESCRIPTION OF THE INVENTION

While the present invention is susceptible of embodiment in its variousforms, there will be hereinafter be described the presently preferredembodiments of the invention with the understanding that the presentdisclosure is to be considered as exemplifications of the invention andit is not intended to limit the invention to the specific embodimentsillustrated.

The gaming chip's body is preferably made of a material having a losstangent of 0.0078 or less. Even more preferably, the gaming chip body ismade of a material having a loss tangent of 0.007 or less, and even morepreferably of 0.005 or less. In some constructions, a material having aloss tangent of 0.001 or less may be desirable for optimal operation ofan embedded RFID.

Furthermore, it has been discovered that a dielectric constant of lessthan 5, and preferably between 3-5, is advantageous for the body of agaming chip including an imbedded RFID operating at 900 MHz. Meanwhile,it has discovered that a dielectric constant of 4.5-15 is advantageousfor a gaming chip to provide better operation of an imbedded RFIDoperating at 2.45 GHz. A gaming chip employing a body having adielectric constant of 5-8 is considered ideal for use with an imbeddedRFID operating at 2.45 GHz.

A gaming chip having a desirable dielectric constant can be manufacturedby combining plastic materials with dielectric ceramic materials.Various plastic materials may be employed. However, semi-rigid PVC isconsidered ideal for numerous reasons including the fact that theweight, feel, and sound provided by a PVC gaming chip has been longrecognized by gamblers as desirable. Meanwhile, acceptable dielectricceramics include aluminum oxide (alumina), magnesium titinate, zincoxide, zirconium barium titanate, strontium titanate (ST), calciumtitanate (CT), magnesium titanate (MT), calcium magnesium titanate(CMT), zinc titanate (ZT), lanthanum titanate (TLT), and neodymiumtitanate (TNT), barium zirconate (BZ), calcium zirconate (CZ), leadmagnesium niobate (PMN), lead zinc niobate (PZN), lithium niobate (LN),barium stannate (BS), calcium stannate (CS), magnesium aluminiumsilicate, magnesium silicate, barium tantalate, titanium dioxide,niobium oxide, zirconia, silica, sapphire, beryllium oxide, andzirconium tin titanate, and combinations thereof.

Of these dielectric ceramics, aluminum oxide (alumina), magnesiumtitinate, zinc oxide, or a combination of aluminum oxide (alumina)blended with zinc oxide or barium sulfate are believed preferreddielectric materials for use within a gaming chip having an RFIDoperating at 900 MHz. Barium zirconate is considered preferred,

alone or in combination with barium titonate or barium sulphate for usewithin a gaming chip having an RFID operating at 2.45 GHz.

The gaming chips of the present invention may be constructed to havevarious dimensions. However, for use in the United States it ispreferred that the gaming chip be constructed in accordance with NevadaGaming Regulation 12.040 which specifies that gaming chips must be 0.130inches thick and have a diameter of 1.55 inches for games other thanBaccarat. For Baccarat, the gaming chips must be 1.55 inches or 1.6875inches. Meanwhile, in accordance with Regulation 12.040, it is preferredthat gaming chips for race books or sports pools have a diameter of1.6875 inches. Though not discussed in detail, the constructions of thepresent invention may also be employed within gaming tokens, such asthose constructed in accordance with Nevada Gaming Commission Regulation12.050, as well as gaming plaques and gaming markers. The Nevada GamingCommission Regulations are incorporated by reference herein in theirentirety.

To form the gaming chips for operating at 2.45 MHz, the plastic,preferably semi-rigid PVC, is blended with the dielectric ceramic,preferably barium zirconate, to have a dielectric constant of 4.5-15, ormore preferably 5-8. The determination of the ratios for the plastic andbarium zirconate can be determined by one skilled in the art withoutundue experimentation, as such ratios will vary depending on theparticular dielectric constant desired and the dielectric constants ofthe PVC and barium zirconate employed. For example, it is thought thatPVC has a dielectric constant which can range from 1-3, while bariumzirconate has a dielectric constant of 10-30 and a loss tangent of about0.006-0.007. After blending, the material is compression molded tocreate gaming chips.

To form the gaming chips for operating at 900 MHz, the plastic, againpreferably semi-rigid PVC, is blended with the dielectric ceramic,preferably aluminum oxide, magnesium titinate, zinc oxide, and/orcombinations thereof, to have a dielectric constant of 5 or less, ormore preferably between 3-5. The determination of the ratios for theplastic and the dielectric ceramic can be determined by one skilled inthe art without undue experimentation, as such ratios will varydepending on the particular dielectric constant desired and thedielectric constants of the PVC and dielectric employed. Again, afterblending, the material is compression molded to create gaming chips.

An RFID is embedded within the gaming chip of the present invention. Ina first embodiment, the gaming chip operates at the 900 MHz rangespecified by the Federal Communications Commission (“FCC”). The 900 MHzISM band is defined in the United States as 915 MHz+/−13 MHz. In stillan additional embodiment of the present invention, the RFIDs for usewith the gaming chip of the present invention operate at 2.4 GHz in arange specified by the FCC as 2.45 GHz+/−50 MHz. In still an additionalembodiment of the invention, the RFIDs for use with the gaming chips ofthe present invention operate at 5.8 GHz which is specified by the FCCas a range of 5.8 GHz+/−75 MHz. However, if an RFID is chosen to operateat the 5.8 GHz range, it is desirable that the gaming chip bemanufactured of a material having an extremely low loss tangent of lessthan 0.001.

RFIDs operating at 900 MHz for use with the present invention can bepurchased by Impinj, Inc. of Seattle, Wash. and NXP, a company foundedby Phillips. Meanwhile, RFIDs operating at 2.45 GHz for use with gamingchips of the present invention can be purchased from Claridy, Inc. ofTaiwan or Neology, Inc. of Poway, Calif.

Though various antenna constructions for use with the RFID may bedesigned by those skilled in the art, in a preferred embodiment, theRFID including antenna and integrated circuit, is sandwiched betweenlayers of high frequency integrated circuit material typically used forintegrated circuit substrates. Acceptable materials are known in theindustry as “Rogers” material. Substrate printed circuit board materialsfrom Arlon, Inc. of Santa Ana, Calif. may also be employed. It ispreferred that the high frequency circuit material has a dielectricconstant of 2.5-4 and a loss tangent of 0.002-0.006. Acceptablematerials include Rogers 4003 and Arlon CLTE.

Preferably, the sandwiching includes three rectangular layers of highfrequency circuit material including top and bottom layers havingsufficient length and width to extend just beyond the extremities of theRFID's antenna. Meanwhile, the middle layer of a high frequency circuitmaterial which preferably has the same dimensions as the top and bottomlayers, but also includes a central hole positioned for receipt of theRFID's integrated circuit. As would be understood by those skilled inthe art, RFIDs are manufactured in various shapes and sizes. Forexample, RFIDs operating at 2.45 GHz are typically rectangular. Forthese RFIDs, it is preferred that the sandwiching includes three layershigh frequency circuit material which are rectangular includingrectangular top and bottom layers having sufficient length and width toextend beyond the extremities of the RFID's antenna. The middle layer ofhigh frequency circuit material is also rectangular with a rectangularcenter hole sized for receipt of the RFID. Conversely, RFIDs operatingat 900 MHz are often round. For these RFIDs, it is preferred that thesandwiching includes three layers high frequency circuit material whichare circular including circular top and bottom layers having sufficientlength and width to extend beyond the extremities of the RFID's antenna.The middle layer of high frequency circuit material is also circularwith a circular center hole sized for receipt of the RFID.

As would be understood by one skilled in the art, this middle layerprotects the integrated circuit during the compression molding processby preventing the outer layers from compressing the integrated circuitand thereby causing unwanted damage. Of importance, the high frequencycircuit material has a dielectric constant and a loss tangentappropriate for not interfering with the operation of the RFID. Inaddition, the layers of materials provide protection for the RFID duringthe compression molding of the gaming chip.

The invention claimed is:
 1. A gaming chip comprising: an RFIDtransmitter; a capsule encapsulating said RFID transmitter, said capsulehaving a loss tangent of 0.002-0.006 and a dielectric constant of 2.5-4;and a cylindrical body having a shape and size of a gaming chipencapsulating said capsule and said RFID transmitter, said body having aloss tangent of 0.007 or less and a dielectric constant of 5-8, and saidbody comprises a blend of a plastic and a dielectric ceramic selectedfrom the group consisting of aluminum oxide, magnesium titinate, zincoxide, magnesium titanate (MT), zinc titanate (ZT), barium zirconate(BZ), barium titonate, barium sulphate, barium stannate (BS), bariumtantalate, and zirconia, and combinations thereof.
 2. The gaming chip ofclaim 1 wherein: said body is a blend of plastic and a dielectricceramic selected from the group consisting of barium zirconate, bariumtitonate and barium sulphate, and combinations thereof.
 3. The gamingchip of claim 1 wherein said RFID transmitter operates in a frequencyband of 915 MHz+/−13 MHz.
 4. The gaming chip of claim 2 wherein saidRFID transmitter operates in a frequency band of 915 MHz+/−13 MHz.
 5. Agaming chip comprising: an RFID transmitter operating in a frequencyband of 915 MHz+/−13 MHz; a capsule encapsulating said RFID transmitter,said high frequency circuit material having a loss tangent of0.002-0.006 and a dielectric constant of 2.5-4; and a body having ashape and size of a cylindrical gaming chip having a thickness of 0.130inch and a diameter of 1.55 inch, said body encapsulating said capsuleand said RFID transmitter, said body having a loss tangent of 0.007 orless and a dielectric constant of 5-8, and said body comprises a plasticand a dielectric ceramic selected from the group consisting of aluminumoxide, magnesium titinate, zinc oxide, magnesium titanate (MT), zinctitanate (ZT), barium zirconate (BZ), barium titonate, barium sulphate,barium stannate (BS), barium tantalate, and zirconia, and combinationsthereof.
 6. The gaming chip of claim 5 wherein: said body is a blend ofplastic and a dielectric ceramic selected from the group consisting ofbarium zirconate, barium titonate and barium sulphate, and combinationsthereof.